Hi,
This could also be recurrent naevus or reappearance of pigment in the scar following surgical removal of a mole as in shave biopsy. Have this checked by your dermatologist for proper management. If the biopsy is fine, there is nothing to be worried about. If a mole changes size, shape or color, or a new one develops in adult life it should be evaluated further to rule out melanoma.
Take care and keep us posted.
what does dr say about this